Water-cooled stoker



@d. 31, 1944. v J 5 BENNETT 2,361,737

WATER COOLED STOKER Original Filed Nov. 1, 1938 2 sheets-sheet 1 FIG. i

INVENTOR JOSEPH s. BENNETT ATTORNEY Uct. 31, 1944.

J. 5. BENNETT WATER COOL-ED STOKER Original Filed Nov. 1, 1938 2 Sheets-Sheet 2 FIG. 5

FIG.2

, INVENTOR JO PH 8. ENNETT- ATTORNEY Patented Oct. 31, 1944 WATER-COOLED STOKER Joseph S. Bennett, Merion, Pa assignor, by mesne assignments, to American Engineering Company, Philadelphia, Pa., a corporation of Pennsylvania Original application November 1, 1938, Serial No. 238,154. Divided and. this application January 1, 1942, Serial No. 425,291

2 Claims.

This application is a division of my co-pending application Ser. No. 238,154, filed November 1, 1938, now Patent No. 2,294,269, and the invention herein involved relates to stoker furnaces, and,

more particularly to stoker furnaces of the fluid cooled type.

One object of the present invention is to provide a generally improved and simplified stoker furnace which employs fluid conducting tubes for cooling the grates and chilling any molten slag in the vicinity thereof. 4

A more specific object is to provide in a stoker furnace of the stated character tuyeres composed of members welded to the tubes provided over the tuyere chambers, the said tuyeres being so constructed and arranged that the heat ab sorbed thereby is rapidly conductedto the fluid circulating in said tubes, whereby said tuyeres remain relatively cool under operating conditions.

Other and further objects will become apparent as the description of the invention progresses.

Of the drawings:

Fig. l is a longitudinal sectional view taken through one of the retorts of an underfeed Stoker, showing the fluid cooled tuyeres associated therewith.

Fig. 2 is a sectional view taken substantially along line 2-2 of Fig. 1 showing the structure and arrangement of a tuyere assembly,

Fig. 3 is an enlarged side elevational view of the construction shown in Figs. 1 and 2 with parts removed to disclose more fully the construction of the tuyeres.

Fig. 4 is a plan view of the construction shown in Figs. 2 and 3, and

' F g. 5 is a sectional view taken transversely of one of the tuyre chambers of a stoker furnace. showing a modified type of tuyere construction.

Referring to the drawings, the numeral l designates generally an inclined grate stoker of the underfeed type consisting of alternately disposed retorts 2 and tuyere rows 3. The side walls of the retorts comprise spaced side plates 4 and 5 supported at the upper and lower ends thereof by any suitable supporting structures 6 and 1 respectively. The bottom of each retort comprises a series of alternately disposed pushers 8 and dead plates 9. Fuel is supplied to the stoker from hoppers l9 disposed exteriorly of the front wall ll of the furnace. The fuel gravitating in said hoppers enters cylinders l2 from which it is fed to the stoker by means of rams l3. Rams I3 are reciprocated by any suitable power mechanism I 4 through a link and lever mechanism IS. The

ill

pushers 8 are also reciprocated by the power mechanism 4'through any suitable link and lev'er mechanism indicated generally at IS.

The tuyere chambers Il disposed between adjacent retorts' are defined at the sides thereof by the retort Side plates 4 and 5, as shown more particularly in Fig. 2. Mounted at the upper end of side plates 4 and .5 are series of sectional tuyere supports l8 and I9. Each tuyere support l8 and I9 has provided at the lower end thereof an inwardly extending flange 20 which rests upon the inwardly extending flange 2| provided at the upper end of side plates 4 and 5. Bolts 22 extending through flanges 20 and 2| rigidly secure the tuyere supports l8 and i9 to side plates 4 and 5, respectively. The upper end of each tuyre chamber I! has extending longitudinally thereof a pair of fluid conducting tubes 23. These tubes have secured thereto a series of bars 24 which in turn'rest upon tuyere supports l3 and I9, as will appear more fully hereinafter.

The tubes 23, as shown in Fig. l, extend downwardly and rearwardly to the end of the stoker, and then are bent downwardly and forwardly as shown at 25, and terminate at the -lower ends thereof in a header 26 disposed near the bottom of the ash pocket 21. The upper ends of tubes 23 are bent vertically, as shown at 28, and extend upwardly along the inner surface of front wall and terminate in a boiler (not shown) or, if preferred, in any suitable header which in turn is connected to the boiler.

The lower end of each retort 2 has provided therein a substantially horizontally extending dead plate 29. Mounted in cooling relation with each dead plate 29 are one or more fluid conducting tubes 3|]. These tubes extend rearwardly from a header 3| mounted in any suitable man- 'ner beneath the stoker, and are bent downwardly in substantially parallel relation with the tubes '23, and terminate at their lower ends in header 2B. Headers 26 and 3| may be connected to the boiler by any suitable downtake and uptake connections 32 and 33 respectively.

Tubes 23 have extending outwardly therefrom fins 31 and 38. These fins extend horizontally. and are then bent downwardly, as shown at 39 and 40, and overlap the vertically extending projections 4| and 42 respectively of tuyre supports I8 and I9. The vertical portions 4| and 42 have provided at the outer sides thereof teeth or projections 43 and 44, which abut the inner sides of the portions 39 and 40 respectively, of fins 31 and 38, thereby forming a series of passages therebetween for draft air. The teeth or projections 43 and 44 also act as cooling vanes for the tuyre supporting members l8 and i9. Tubes 23 have also provided thereon at spaced points along the length thereof downwardly extending bolts 45 and 46, to which the supporting bars 24 are secured. These bolts are shouldered as shown at 41 and 48, to limit the downward movement of and yet are free to expand and contract by virtue of the sliding supports provided by bars 24. Bars 24 also act as tie members to prevent lateral displacement of the tubes 23 under load. Draft air is supplied to the stoker by means of a plenum chamber 52, which in turn receives air under pressure from any suitable fan or blower mechanism (not shown) through a communicating passage 53.

As shown more particularly in Figs. 2, 3 and 4, each tube 23 has also secured thereto a series of substantially horizontal fins 16 extending in wardly thereof. The fins 16"on one tube extend into the spaces 11 between the fins 16 of the adjacent tube thereby forminga series of horizontal passages for draft air. It will be observed upon reference to Figs. 3 and 4 that the fins 16 on each tube overlap longitudinally with each other. Thus by this lateral, as well as longitudinal overlapping arrangement of the fins 16 the passage of siftings between the tubes is reduced to a minimum. It is also seen that each tube 23 is free to expand and contract without interfering with the adjacent tube or with the supports therefor. V

Fig. 5 discloses a modification of the present invention wherein each tuyre chamber 89 has provided at the upper end thereof three spaced tubes 8|, 82 and 83. Tube 8| has provided at the opposite sides thereof longitudinally extendingifins 84 and 85. Tubes 82 and 83 have extending laterally from the inner sides thereof fins 86 and 81 disposed'beneathand in overlapping relation with fins 84 and 85, respectively. and

forming therewith passages for draft air. Tubes 82 and 83 have also extending laterally from the outer sides thereof fins 88 and 89, which, like fins 31 and 38, shown in Fig. 2, overlap the upper ends of the tuyere supports 99 and 9|, respectively. Fins 88 and 89 are similar in con? struction and arrangement to the fins 31 and 38, and accordingly a detailed description thereof is unnecessary. k

Tubes 8|, 82 and 83 have depending therefrom at spaced intervals bolts 92, 93 and 94, to which are secured a supporting bar 95. Supporting bars 95 are mounted in the longitudinally extendingrecesses provided in tuyre supports 90 and 9|, and accordingly effectively support the tuyre section, and at the same time permit longitudinal expansion and contraction of the tubes.

The tuyre arrangement associated with tubes BI, 82 and 83 are provided for the purpose of illustration to show that applicants invention is applicable to arrangements comprising more than two fluid conducting tubes.

In all of the constructions hereinbefore described, the fins are welded to the tubes, thereby providing an intimate thermal contact between the fins and tubes. The fins are thus maintained relatively cool during operation of the furnace, and consequently burnouts are reduced to a minimum. The various constructions hereinbefore described also are of a simplified nature, and therefore may be manufactured at a relatively I low cost.

While the embodiments herein shown and described are admirably adapted to fulfill the objects primarily stated, it is to be understood that it is not intended to limit the invention thereto, since it may be embodied in other forms, all coming within the scope of the claims which follow.

What is claimed is:

1. A stoker grate comprising a series of spaced, longitudinally extending tuyre sections, each of said tuyre sections consisting of fluid conducting tubes extending longitudinally thereof and in substantially parallel relation, supporting means for said tubes comprising a pair of spaced side walls, fins extending laterally from one of said tubes, said fins being disposed at an angle to the axis thereof, fins extending laterally from other of said tubes and disposed in overlapping relation with said first mentioned fins, and said fins overlapping longitudinally thereby reducing the passage of siftings therebetween, and additional fins extending from said tubes-and disposed in overlapping relation with the upper ends of said side walls, thereby defining additional passages for draft air.

2. A stoker grate comprising a series of spaced, downwardly inclining, longitudinally extending tuyre sections, each of said tuyre sections consisting of downwardly inclining tubes extending longitudinally thereof and in substantially parallel relation, supporting means for said tubes comprising a pair of spaced side walls, a series of substantially horizontal fins extending inwardly from one of said tubes, a second series of substantially horizontal fins extending inwardly from the other of said tubes, the fins of each of said series extending into the spaces between the fins of the other series thereby forming a series of substantially horizontal passages for draft air, the said fins of each of said series being disposed in overlapping relation longitudinally of said tubes thereby reducing the passage of fuel siftings therebetween to a minimum, and fins extending laterally from the outer sides of said tubes, said last mentioned fins overlapping said supporting means and forming therewith additional passages for draft air.

JOSEPH S. BENNETT. 

